Heart failure (HF) is one of the most common causes of in-hospital mortality for patients with cardiac diseases. Heart failure is typified by the inability of the heart to pump enough blood to meet the body's metabolic requirements for oxygen and nutrients leading to discrepancies between myocardial oxygen supply and demand.
The left ventricle's inability to generate sufficient cardiac output, i.e. HF, is commonly associated with left ventricular systolic (emptying of left ventricular chamber) dysfunction, but its symptoms may also arise as a result of diastolic (filling of left ventricular chamber) dysfunction (with or without the presence of systolic dysfunction). The term “diastolic dysfunction” refers to changes in ventricular diastolic properties that have an adverse effect on ventricular diastolic pressures and ventricular filling.
An integral part of normal diastolic filling is the contribution of the left ventricular (LV) elastic recoil forces to the LV filling. Elastic recoil forces are generated within healthy myocardium during systolic shortening. The magnitudes of elastic recoil forces are inversely proportional to the volume of the LV, i.e., they increase as the LV volume decreases. Their contribution is important in early diastole because they allow rapid and enhanced early filling by assisting the expansion of the left ventricle.
In a case of ventricular enlargement and/or the decrease of myocardial function due to hypertrophy the left ventricular elastic recoil forces may be diminished or nonexistent, therefore ceasing to assist early ventricular filling and leading to an increase of the ventricular filling pressure.
Intervention to alleviate the resultant symptoms of the physical changes described above may offer great benefit to patients with heart disease. Administration of vasodilators, diuretics, sodium channel blockers, and inotropic agents have been used to reduce the number of acute events and slow the advance of disease, but cannot reverse the physical changes to the heart. Surgical intervention can reduce the volume of the ventricle such that cardiac function is improved but carries high risk for the patient. Other less invasive modes of intervention offer improved function while reducing risk for the patient during and after the procedure.